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ring ridge question
https://slantsix.org/forum/viewtopic.php?t=47626		 Page 1 of 2
Author:  kielbasa [ Wed Jan 18, 2012 7:23 pm ]
Post subject:  ring ridge question
looking over pictures i took during my build, i came to realize something i had kinda overlooked and forgotten. i had some ring ridges. i took the block to the machine shop to get bored, or honed whatever needed to be done.

all they did was hone, and insured me it would be just fine, so thats the reason why i just kinda overlooked things. he said he was not comfortable boring to .080, since it was already at .060. :-/

it is not completly 360 degrees around the cyl, maybe only half at most, #2 seems to have the most.

now thinking about it, im hoping this wasnt a huge mistake and ill just be fine, but now i just cant get it off my mind, i remember not feeling much of a grove, if any on my finger nail, its mostly just noticable by eye. please give me input, if i need to tear this thing apart before i get into more trouble let me know. im very bugged, and irritated

Image
Author:  ceej [ Wed Jan 18, 2012 8:29 pm ]
Post subject: 
There will almost always be a visible point that shows where the top ring stops. if there was no ridge, something that you can feel with your nail, then your fine. Once the hone went over it, it should be good to go.

What did the bore size mic out to? That's what's important. If it cleaned up and still was in spec for the 0.060" over pistons, then it shouldn't be a problem.

Machinists tend to get all worked up about overboring into the larger ranges. I've found 0.100" Overbore pistons for the slant in the past. That's getting out into territory where core shift can come into play. Generally, unless your trying to eke out every single cubic inch you can, only bore to the smallest size that cleans. Save the 0.080" over pistons for the day the cylinders won't clean up for the 60's.

If you want a real argument, take your head to a chevy guy and ask him to cut it 0.100" They get all worked up about that. :lol:

CJ
Author:  kielbasa [ Wed Jan 18, 2012 8:42 pm ]
Post subject: 
so your saying i should be just fine?
Author:  kielbasa [ Thu Jan 19, 2012 7:47 am ]
Post subject: 
Am I good here?
Author:  Doc [ Thu Jan 19, 2012 8:39 am ]
Post subject: 
Quote:
...What did the bore size mic out to? That's what's important. If it cleaned up and still was in spec for the 0.060" over pistons, then it shouldn't be a problem...
Top to bottom taper is the concern so the question is,: how "straight & round" are the bores?
The FSM puts the limit at .007, for "patch job" street engines, I have run up to .010 with-out major issues.
DD
Author:  CNC-Dude [ Thu Jan 19, 2012 9:31 am ]
Post subject: 
If your block was running fine at .060 over, it should be fine at .080 over. It only removes .010 from each side of the cylinder wall to go that extra amount. As has been said, if you can catch the ridge with a finger nail, it really should be bored. The main reason is the very top inside edge of the ridge is radiused from piston rock and ring wear, when you put new rings back in the cylinder, the top edge of the rings are new and sharp, and when they are forced into the radius of the ridge at the pistons top travel it can damage the top ring very easily. Its kinda like a round peg in a square hole sort of fit.
Author:  kielbasa [ Thu Jan 19, 2012 1:52 pm ]
Post subject: 
I'm not worried about it catching, I'm worried about leak down. Or am i thinking too much
Author:  ceej [ Thu Jan 19, 2012 2:38 pm ]
Post subject: 
As long as the cylinders were within specification, and the rings properly gapped, you should be fine.

Ask your builder what measurements they got, and what eccentricity and taper were found.

CJ
Author:  slantzilla [ Thu Jan 19, 2012 2:52 pm ]
Post subject: 
From that picture I wouldn't put that back together if I wanted it to last. If that wear is in the ring travel it will tear up the ring.
Author:  ceej [ Thu Jan 19, 2012 3:01 pm ]
Post subject: 
Geeze. I thought I was seeing the tops of pistons. That is pretty bad. Was this after honing? :shock:

Zilla's right. Bore it.

CJ
Author:  sandy in BC [ Thu Jan 19, 2012 3:21 pm ]
Post subject: 
I think I would get it bored and honed at a different facility.
Author:  slantzilla [ Thu Jan 19, 2012 4:02 pm ]
Post subject: 
Quote:
Geeze. I thought I was seeing the tops of pistons. That is pretty bad.

CJ
Dude, you need glasses. :shock:

:lol: :lol:
Author:  kielbasa [ Thu Jan 19, 2012 5:47 pm ]
Post subject: 
just great :\ thats what i get for not really thinking about it. thanks..
Author:  kielbasa [ Thu Jan 19, 2012 6:03 pm ]
Post subject: 
im gonna eat a whole gasket kit, about $100 bucks worth, pistons and rings.... and i have to find .080 overs... anybody have a lead on some .080 over pistons and rings?
Author:  slantzilla [ Fri Jan 20, 2012 3:01 am ]
Post subject: 
You can probably find a different block cheaper than a set of .080" pistons. Don't know about out there, but here I can't give a block away. :oops:
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